public int CompareComponentPositions(FileComponent c1, FileComponent c2)
{
if (c1 == c2)
return 0;
int p1 = fileStructure.IndexOf(c1);
int p2 = fileStructure.IndexOf(c2);
if (p1 == -1 || p2 == -1)
throw new NotFoundException();
return p2.CompareTo(p1);
}